December 9, 2013
Ancient Martian Lake May Have Supported Microbial Life
[ Watch the Video: Evidence Of Ancient Lake Found Within Gale Crater ]
Lee Rannals for redOrbit.com - Your Universe Online
NASA scientists announced at the American Geophysical Union meeting in San Francisco on Monday that they have discovered the fossil remains of a lake inside Gale Crater. The scientists say that this lake would have existed for as long as tens of thousands of years, which is long enough for life to have evolved.
Curiosity revealed that the lake, roughly the size of New York’s Finger Lakes, contained chemical and mineral conditions needed to support microbial life. The lake waters held low salinity at just the right acidity and all the chemicals needed to support living organisms.
NASA soil mineralogist Douglas Ming, who took part in the new research, said that although this isn’t proof there was once life on Mars, it is proof that the Red Planet had conditions favorable for life.
“There's pretty good evidence for that. We have an environment that is very much like on Earth,” Ming said at the meeting.
The team analyzed a set of sedimentary rock outcrops at a site named Yellowknife Bay in Gale Crater, which lies near the Martian equator. This analysis reveals that Gale Crater sustained at least one lake around 3.6 billion years ago. The data shows the lake was calm and likely had fresh water, containing biological elements like carbon, hydrogen, oxygen, nitrogen and sulfur.
“What we have found is that Gale Crater was able to sustain a lake on its surface at least once in its ancient past that may have been favorable for microbial life, billions of years ago. This is a huge positive step for the exploration of Mars,"stated Professor Sanjeev Gupta, a member of the Curiosity team from the Department of Earth Science and Engineering at Imperial College London and a co-author on the paper published in the journal Science.
"It is exciting to think that billions of years ago, ancient microbial life may have existed in the lake's calm waters, converting a rich array of elements into energy. The next phase of the mission, where we will be exploring more rocky outcrops on the crater's surface, could hold the key whether life did exist on the red planet."
The researchers believe that habitable conditions in the Yellowknife Bay area may have persisted for millions to tens of millions of years. During that time, rivers and lakes appeared and disappeared. Even when the lake bed dried up, the subsurface was still wet, which is indicated by mineral veins deposited by underground water into fractures in the rock.
"This habitable environment existed later than many people thought there would be one," John Grotzinger of Caltech said in a statement. "This has global implications. It's from a time when there were deltas, alluvial fans and other signs of surface water at many places on Mars, but those were considered too young, or too short-lived, to have formed clay minerals. The thinking was, if they had clay minerals, those must have washed in from older deposits. Now, we know the clay minerals could be produced later, and that gives us many locations that may have had habitable environments, too."
Next, the team plans to use the rover to explore the crater for further evidence of ancient lakes or other habitable environments in the thick pile of sedimentary rocks scattered around the crater.